1. Field of the Invention
The invention relates generally to combustion heaters and is more specifically directed to portable stoves or furnaces which may be employed with or without a pot for heating and especially for cooking foodstuffs and for boiling of water with combustible materials under relatively primitive conditions.
2. Description of the Prior Art
Field stoves and domestic heaters for cooking and heating water have been devised in considerable variety ever since cast iron and especially sheet iron became widely available. Benjamin Franklin made the first great advances in stove and heater design around 1740. Count Rumford (Benjamin Thompson) during the decades around 1800 devised a variety of stoves and pot-and-fire units described and depicted in the book entitled FIRE by John W. Lyons (Scientific American Books, Inc., 1985), a broad and scientific overview of the topic by the Director of the National Engineering Laboratory of the National Bureau of Standards and himself a world authority in the technology of fire.
It is clear that Count Rumford gained profound insights through scientific experiments and understood, along with Lavoisier, George Stahl and Robert Boyle, apparently for the first time in history the true nature of heat and some of the fundamental properties of fire as a physical/chemical phenomenon as well as the heat transfer mechanisms of conduction, convection and radiation. Applying this wealth of new knowledge, Count Rumford devised a wide variety of means for improving control of fire and of enhancing heat transfer from a confined fire, as in a furnace or stove, to the contents of a vessel as for heating water or cooking in a pot.
Count Rumford's insights are reflected in patents issued since his time such as U.S. Pat. Nos. 118,095 for "Improvement in Portable Furnaces" (1871); 320,799 and 355,696, both granted in 1887 for "Portable Furnace"; 936,482 for a "Portable Stove" issued in 1909; and 2,290,802 issued in 1942 for a "Cooking Stove." None of these prior art devices integrates in one system all primary functions and properties now known to be requisite to realization of high efficiency and high rate of heating in a practical and simple combination of elements.